Mary Bishop listens as her partner Sharon Baldwin speaks about the status of appeals in the ongoing Oklahoma same sex marriage fight during a news conference at the Dennis R. Neill Equality Center in Tulsa, Okla., Monday, March 17, 2014. (AP Photo/Tulsa World, Michael Wyke)

TULSA, Okla. (AP) — Oklahoma’s gay marriage ban demeans same-sex couples and their children by signaling to the world that their relationships are secondary to traditional families, opponents of the state law say in a new legal filing.

The argument came in a 102-page document filed Monday on behalf of Mary Bishop and Sharon Baldwin in the 10th Circuit Court of Appeals in Denver. Bishop and Baldwin, who have been together for more than 15 years, are suing to be allowed to marry in Oklahoma.

Their attorneys argue in the filing that the ban “demeans and humiliates these couples and their children, conveying to them, to family, to friends, to neighbors, to classmates, to teachers, to colleagues, to employers, to officials, to governments, and to all the world that their relationships are unworthy and second-tier,” the document stated.

The filing came in response to a brief filed last month by the Alliance Defending Freedom that said legalizing gay marriage would harm children, undermine society and make traditional marriages unstable.

U.S. District Judge Terence Kern ruled in January against Tulsa County Court Clerk Sally Howe Smith, whose office refused to grant Baldwin and Bishop a marriage license. In his ruling, Kern said Oklahoma, by enforcing the ban, violates the U.S. Constitution’s Equal Protection Clause because it precludes same-sex couples from receiving an Oklahoma marriage license.

Jim Campbell, legal counsel for the ADF, said in a statement that the district court “sidestepped the real reasons for Oklahoma’s definition of marriage.”

“Rather than upholding the marriage amendment, the court endorsed the recently conceived notion that marriage is about special government recognition for adult relationships,” Campbell said.